center one div above two other divs

问题

I would like to achieve this situation:

The page contains 4 divs in total. The main layer is divided in 3 divs. Above div1 and div2, another div(div4) must be floating above them in the middle of these 2 divs.

current code:

body {
position:relative;
}

div1 {
 // nothing
}

div2 {
 // nothing
}

div3 {
 // nothing
}

div4 {
 z-index: 10;
 position: absolute;
 top: 550px;
 left: 0;
 margin-left: auto;
 margin-right: auto;
 width: 50%;
 padding: 50px;
}

I would appreciate it if anyone could give me a heads up.

Thanks in advance!

回答1:

If your issue is just how to get that layout this can help:

* {
  margin: 0
}
html,
body {
  height: 100%;
}
div {
  height: 33.3%;
}
.one {
  background: red;
}
.two {
  background: green;
}
.three {
  background: blue;
}
.four {
  position: absolute;
  background: yellow;
  top: 17%;
  left: 30%;
  width: 40%;
}

<div class="one"></div>
<div class="two"></div>
<div class="three"></div>
<div class="four"></div>

---

But this is just visual boxes, if you have more requirements can be a little tricky.

来源：https://stackoverflow.com/questions/28196741/center-one-div-above-two-other-divs